Plasma processing method

Abstract

In a plasma processing method, a position in height direction of an upper surface of a focus ring surrounding an edge of a substrate mounted on a supporting table in a chamber of a plasma processing apparatus is set such that the position in height direction of the upper surface of the focus ring mounted on a mounting region of the supporting table is lower than a reference position that is a position in a height direction of an upper surface of the substrate. Plasma is generated in the chamber to perform plasma processing on the substrate in a state where the position in the height direction of the upper surface of the focus ring is maintained. A negative DC voltage is applied to the focus ring in a state where the position in height direction of the upper surface of the focus ring is maintained during the plasma generation.

The invention claimed is: 
     
       1. A plasma processing apparatus comprising:
 a plasma processing chamber; 
 a support disposed in the plasma processing chamber, the support having a central region and an annular region, the annular region surrounding the central region; 
 an annular member disposed on the annular region of the support; 
 a driving unit configured to move the annular member such that an upper surface of the annular member is maintained at a position lower than an upper surface of a substrate placed on the central region of the support; 
 a measuring device configured to measure a degree of inclination of a recess or an opening formed in an edge region of the substrate; 
 a DC power source configured to apply a negative DC voltage to the annular member; and 
 a controller configured to determine an absolute value of the negative DC voltage according to the degree of inclination. 
 
     
     
       2. The plasma processing apparatus of  claim 1 , wherein the controller is configured to control an incident direction of ions on an edge region of the substrate placed on the central region of the support, by adjusting the absolute value. 
     
     
       3. The plasma processing apparatus of  claim 1 , wherein the controller is configured to set the absolute value to a first value smaller than a reference value, thereby causing an incident direction of ions on an edge region of the substrate placed on the central region of the support to be inclined inwardly with respect to a vertical direction. 
     
     
       4. The plasma processing apparatus of  claim 3 , wherein the controller is further configured to set the absolute value to a second value greater than the reference value, thereby causing the incident direction of ions to be inclined outwardly with respect to the vertical direction. 
     
     
       5. The plasma processing apparatus of  claim 1 , wherein the controller is configured to set the absolute value to a value greater than a reference value, thereby causing an incident direction of ions on an edge region of the substrate placed on the central region of the support to be inclined outwardly with respect to a vertical direction. 
     
     
       6. The plasma processing apparatus of  claim 1 , wherein the amount of inclination is an inclination angle of the recess formed in the film with respect to a vertical direction. 
     
     
       7. The plasma processing apparatus of  claim 1 , wherein the amount of inclination is an amount of deviation in a horizontal direction between upper and lower ends of the recess formed in the film. 
     
     
       8. The plasma processing apparatus of  claim 1 , wherein the absolute value of the negative DC voltage is determined based on a table or a function including a relation between the amount of inclination and a voltage value of the negative DC voltage is preset. 
     
     
       9. The plasma processing apparatus of  claim 1 , wherein the amount of inclination is an inclination angle of the opening of the mask with respect to a vertical direction. 
     
     
       10. The plasma processing apparatus of  claim 1 , wherein the amount of inclination is an amount of deviation in a horizontal direction between upper and lower ends of the opening of the mask. 
     
     
       11. The plasma processing apparatus of  claim 1 , wherein the absolute value of the negative DC voltage is determined based on a table or a function including a relation between the amount of inclination and a voltage value of the negative DC voltage. 
     
     
       12. A plasma processing apparatus comprising:
 a plasma processing chamber; 
 a support disposed in the plasma processing chamber, the support having a central region and an annular region, the annular region surrounding the central region; 
 an annular member disposed on the annular region of the support; 
 
       a driving unit configured to move the annular member such that an upper surface of the annular member is maintained at a position lower than an upper surface of a substrate placed on the central region of the support; and
 a DC power source configured to apply a DC voltage to the annular member. 
 
     
     
       13. A plasma processing apparatus comprising:
 a plasma processing chamber; 
 a support disposed in the plasma processing chamber, the support having a central region and an annular region, the annular region surrounding the central region, 
 an annular member disposed on the annular region of the support, an upper surface of the annular member being lower than an upper surface of a substrate placed on the central region of the support; 
 a measuring device configured to measure a degree of inclination of a recess or an opening formed in an edge region of the substrate; 
 a DC power source configured to apply a DC voltage to the annular member; and 
 a controller configured to determine a value of the DC voltage according to the degree of inclination.